Advanced process simulation with APROS for VVER-91, the next generation reactor design for VVER-1000

The paper describes the capabilities of APROS code in the simulation of the VVER-91 concept. The VVER-91 models realized with APROS are described and a short overview of the various types of analysis performed is given. Particular emphasis is paid on the ATWS analyses performed with APROS. The results of APROS in a steam line break ATWS analysis are reported in detail and compared to the results of the HEXTRAN code, that has been used extensively in the ATWS and other accident analyses of VVER-91